Until last month, Mumbai’s Royal Opera House, the only surviving opera house in the country, hadn’t seen a performance in eight decades.

The historic three-level structure built in 1912 re-opened to the public only in October 2016, after a six-year-long rennovation project restored a once-crumbling edifice to its former glory. Less than a year later, an all-Indian double cast, accompanied by the Symphony Orchestra of India led by an Indian-origin conductor, took to the stage at the...